A food additive that has been used for decades is stirring up controversy. We talk with a Chicago researcher who is in the midst of clinical trials to uncover its potential hazards. Read an article about carrageenan.

Brookfield Zoo is standing tall today after the debut of the 59th baby giraffe born on its grounds. At 5-foot-9 and 173 pounds, the calf was born 11 days ago to first-time mom Jasiri, and dad Hasani. Watch a web extra video of the giraffe's birth.

We revisit an exhibit that takes a revealing look at animals from the inside -- out. Ash-har Quraishi takes us behind the scenes at the Museum of Science and Industry. Read an article and view a slideshow.

Are some of the plants in your garden already dying? Or are the top-heavy plants face down in the mud? The Chicago Botanic Garden’s Eliza Fournier joins us. Read her summer gardening tips.

Fifty-two million years ago, after the extinction of dinosaurs, a tropical lake basin surrounded by volcanoes was home to thousands of diverse species. Now that basin is known as Wyoming's Fossil Lake, with some of the most well-preserved fossils in the world. The Field Museum's Lance Grande brings us some of his fantastic finds from The Lost World of Fossil Lake. Read an interview with Grande and view photos.

Heavy rains swept through the Chicago area Wednesday morning challenging commuters and the engineers at the Metropolitan Water Reclamation District. Read an article.

Computer scientists are partnering with physicians to take next-generation virtual reality to the extreme. We revisit Ash-har Quraishi's exploration inside the CAVE2 in tonight's edition of Scientific Chicago. Read an article and view a slideshow.

The U.S. Supreme Court unanimously ruled that human genes are off-limits for patent protection. Read the full opinion, and a Q&A with a bioethics professor about the impact of the ruling on the medical community.

A flood watch is in effect for the region from 4:00 pm Wednesday afternoon until 4:00 am Thursday morning. We chat with WGN-TV’s chief meteorologist Tom Skilling about what to expect, and how to protect your family and property.

Ash-har Quraishi has the story of how Chicago played a pivotal role in sci-fi cinematic history.

What can the songs of the Zebra finch tell us about the development of language in humans? Our science guy, Neil Shubin, tells us more in this edition of Scientific Chicago.

A food additive that has been used for decades is stirring up controversy. We talk with a Chicago researcher who is in the midst of clinical trials to uncover its potential hazards. Ash-har Quraishi has the story in tonight's Scientific Chicago.

Computer scientists are partnering with physicians to take next-generation virtual reality to the extreme. Ash-har Quraishi goes inside the CAVE2 in tonight's edition of Scientific Chicago.

After one of the wettest Aprils in Chicago history, Eliza Fournier from the Chicago Botanic Garden joins Chicago Tonight at 7:00 pm to offer spring gardening pointers.

View a slideshow of flood photos from Chicago Tonight viewers, producers and reporters. Submit your flood photos here and we will add them to the photo gallery.